BIOL 0130 Lecture Notes - Lecture 4: Tapetum Lucidum, Far-Sightedness, Near-Sightedness
3 Sep 2016
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Document Summary
The perception of light is a specialized type of photoreception. Photoreceptors contain photo-pigments, which change shape when they absorb light. Shape change sets off a series of chemical reactions inside the photoreceptor cell that ultimately produces a receptor potential. Then passes through aqueous humor (a chamber filled with a watery fluid) Amount of light entering eye adjusted by the iris (pigmented muscular tissue) which regulates the size of the pupil (the opening in its center) Light passing through the pupil strikes the lens, which focuses the image. Behind the lens is vitreous humor (larger fluid filled chamber) which helps maintain the shape of the eyeball. After passing through the vitreous humor, light reaches the retina, where it is converted into action potentials that are conducted to the brain. Near-sighted also known as myopia eye is oval shaped (longer) the light focuses in front of the retina corrected with a concave lens (lens is thinner in the middle)
